Mold for casting metals



1,640,84 Aug. 30, 1927. a E MAGILL 3 MOLD FOR CASTING METALS Filed Nov.22, 1924 2 Sheets-Sheet l INVENTOR A ORNEY Au v 30, 1927.

C. E. MAGILL MOLD FOR CASTING METALS Filed Nov. 22, 1924 2 Sheets- Sheet2 mam-um INVENTORI r I AQRNt-ZW Patented Aug. 30, 1927.

UNITED STATES PATENT OFFICE.

CHARLES E. MAGILL, 0F CLEVELAND, OHIO, ASSIGNOR TO THE ALUMINUM COMPANYOF AMERICA,

01 CLEVELAND, OHIO, A CORPORATION.

MOLD FOB CASTING METALS.

Application filed November 22, 1924. Serial No. 751,657.

This invention relates to composite molds for casting metallic articlesparticularly molds comprising a cope, and a drag in which a major partof the casting is formed.

It also relates to a mold for casting met-- als comprising a dragcomposed principally of granular material in which a major part of thecasting is formed, and a cope composed principally of metal.

The ordinary sand molds comprising a drag and a cope, when employed forfairly large castings the major part of which are formed in the drag,are not capable of the highest degree of etlicient operation due tovarious factors, including the necessity of having separatemolding'machines'for forming the drags and copes separately, togetherwith other apparatus. such as cranes etc., to manipulate such machinesand handle the material for use therewith. Furthermore, with sand copesmany castings are defective because of cope drops, that is, sand fromthe cope dropping into the casting cavity before or during the castingoperation.

I have, however, by my invention pro-vided a mold in which all danger ofcope drops is eliminated and which can be operated much more rapidlythan the molds now in use and with considerably less labor, material andequipment, thereby greatly decreasing the present cost to manufacturer.One important saving is in labor previously required in making copeswhile another saving is in removing all restraint on the molding of thedrags due to the slower molding of the copes. It will be understood thatthe drag molding is faster than the cope molding and that since thedrags and copes must move along together. the speed of cope moldingdetermines the speed of drag molding.

, At the same time my improved mold produces castings possessingproperties heretofore unobtainable in the ordinary molds except by theuse of numbers of metal chills inserted in the cope during the moldingoperation. v

In the drawings accompanying this specification and forming a partthereof:

Fig. 1 is a top plan view of a mold constructed in accordance with myinvention, the outlines of the casting being indicated in dotted lines.

Fig. 2 is a vertical, longitudinal cross section taken on line 22 ofFig. 1.

Fig. 3 is a vertical, transverse cross section taken on line 3-3 of Fig.1, and

Fig. 4 is a bottom plan view of a modified form of cope.

In the drawings Numeral 1 designates a flask for the drag or bottomportion of a mold, the flask 1 consisting of a bottom plate 2 and fourupri ht side walls 3 within which sand 4 or 0t er similar moldingmaterial may be packed and formed with a cavity 5 for a major part orall of an article 6, in this case a crank case for an automobile engine.The drag also carries cores 7 suitabl supported within the castingcavity 5 to orm certain walls of the cavity against which the moltenmetal may be cast in forming. the casting 6 as will be understood bythose skilled in the art. The drag, including the above described parts,is substantially the same as the drags now in common use in the sandfoundry industry.

The cope 8 consists of a thin metal plate of suitable size to rest onthe top of and be supported by the upright walls 3 of flask l and havingend extensions 8 to serve as supports by which it may be carried. It isprovided with a plurality of perforations extending therethrough andcommunicating with the drag at points immediately above or adjacent tothe casting cavity when assembled with the drag. Certain of theseopenings, indicated at 9, preferably lead directly into the castingcavity while opening 10 leads into the casting cavity and communicateswith the casting cavity through a runner 11 and gates 12 leading tovarious parts of the casting cavity, as the nature of the castingnecessitates. Each of the openings 9 and 10 has a liner composed ofrefractory heat insulating material toprevent contact of the moltenmetal with the sides of the openings. These liners which are indicatedat 13 consist pref drag at one side of the for the casting. Althoughopenings 9 are here employed as risers and opening as a pouring gate, itwill be understood that molten metal in some instances may be poureddirectly into the casting cavity through one or more openings 9, ifdesired. It will be noted that cope 8 forms certain walls of the castingcavity, as more clearly indicated in Fig. 3. IVhere the cope thusconstitutes walls of the casting cavity it acts to expedite chilling of-the molten metal coming into contact therewith, and thereby tends toproduce dense, nonporous cast metal which at such points of contact isparticularly advantageous when such metals as aluminum 'alloys are beingcast. It is desirable, however, to maintain large bodies of molten metalout of contact with the cope except at places where a chilling elfect isdesired, since the molten metal is unduly in cope 8 to receive thiscover or it may supported in recesses in the mold material 4.

In operating a mold of my construction, J. pattern (not shown) is lacedon a plate (not shown) within the ask 1, sand 4. is rammed around thepattern after which the flask is turned over into the position shown inFig. 2, the pattern extracted and the cores 7 fittedinto place. Runner11 and gate 12 are cut in the sand 2 and cover 14 placed thereover. Thencope 8 with liners 13 in the openings 9 and 10 is placed on flask 1.Molten metal is then poured through opening 10 into runner 11 and feedsinto casting cavity 5 through gates 12 filling the cavity and risinginto liners 13 above the cope. After the molten metal has solidified theliners 13 and cope 8 are removed and the.

gate and riser metal which solidifies in the.

liners 13.

In Fig. 4 I have shown a slightly modified form of my invention wherethe cope 8 has cores secured to its under face. In this particular casethe cope is for use in making crank case castings for automobileengines, the cores 15 being provided for coring out the crank shaftbosses. When the cope is provided with cores attached thereto any dangerof misalignment of these cores is avoided as contrasted with the use ofseparate sand or metal cores. as shown in Fig. 2.

Although I have shown substantially square liners l3 and substantiallysquare holes 9 and 10 in the cope, I may make the holes 9 and 10 roundand employ therewith round liners. Such liners may be readily fittedinto the openings 9 and 10 with close fitting engagement by having theouter surfaces of the liners slightly larger in diameter than thecorresponding diameter of the openings 9 and 10, so that when the linersare inserted in the opening and rotated back and forth slightly, theywill seat on the cope and have close fitting engagement with the wallsof the, openings. But whatever the cross section of the liners 13 maybe, it is desiri able that they engage closely with the side walls ofthe openings of which they constitute the liners. In case the liners donot fit closely to the cope, molten metal from the casting cavity mayform fins between the cope and liners which act as anchors when thecasting shrinks in cooling and may cause breakage of the castingintermediate such anchors. For example, if such fins were formed aroundthe liners at either end of thev casting 6 (shown herein) the ends ofthe castings would be more or less fixed or anchored and as the castingshrinks in cooling a crack or cracks across the intermediate portion, ofthe casting might result;

With close contact between the liners and cope no such danger exists.

Having thus described my invention so that those skilled in the art maybe enabled to practice the same, what I desire to secure by Letters-Patent is defined in what is claimed, it being understood that changesnot involving invention may be made in the details hereinabove shown anddescribed, without departing from the spirit and scope of my invention.

What is claimed is:

1. A mold for casting metallic articles comprising a drag provided witha casting cavity for a major portion of the article to be cast, and acope composed of metal and provided with a plurality of perforations inwhich molten metal may solidify, the perforations extending through thecope-and communicating with the said casting cavity, the cope beingremovablefrom and without contacting with solidified metal in theperforations.

2. A mold for casting metallic articles comprising a drag provided witha casting cavity for a major portion of the article to be cast and withcores in. the said cavity. the said drag. and cores being composed ofgranular material, and a cope composed of metal and provided with aplurality of perforations in which molten metal may solidify, theperforations extending through the cope and communicating with the saidcasting cavity, the cope being removable from and without contactingwith solidified metal in the perforations.

3. A mold for casting metallic articles comprising a drag composed ofgranular material and provided with a casting cavity for a major portionofthe article to be cast, and a cope composed of metal and provided witha plurality of-perforations in which molten metal may solidify, theperforations extending through the cope and communicating with the saidcasting cavity, the cope being removable from and without contactingwith solidified metal in the perforations.

4. The combination set forth in claim 1 in which each perforation of thecope is provided With a liner composed of refractory material.

5. The combination set forth in claim 1 in which each perforation in thecope is provided with a refractory liner extending through and wellabove the cope.

6. In a mold for casting metallic articles the combination of a flask,granular material in the flask provided-with a casting cavity, COIKS inthecasti'ng cavity, a thin metal cope on the flask forming top walls ofthe casting cavity and provided with perforations in which molten metalmay solidify, the perforations extending through the cope andcommunicating with the casting cavity, the

cope being removable from and without contacting with solidified metalin the perforations.

7. In a mold for casting metallic articles, the combination of a flask,granular material in the flask provided with communicating open toppedcasting and runner cavities, a thin metal cope on the flask constitutinga cover for the said casting cavity, against which molten metal is cast,and a heat insulating'cover for the said runner cavity between therunner and the cope, the said cope having a plurality of perforationsfor a pouring gate and risers extending therethrough and communicatingwith the said casting and runner cavities.

8. In a mold for casting metallic articles, the combination of a flask,granular material in the flask provided with a casting cavity, core-s inthe casting cavity, a thin metal cope on the flask forming top walls ofthe casting cavity and provided with perforations, liners of refractorymaterial in the said perforations having close fitting contact with thesides of the perforations; the said perforations in the cope beinglarger than the greatest cross sectional dimensions of metal solidifyingtherein. I

9. In a mold for casting metallic articles, the combination of a flask,granular material in the flask provided with communicating open toppedcasting and runner cavities. a thin metal cope on the flask constitutinga cover for the said casting cavity, and a heat insulating cover for thesaid runner cavity between the runner and the cope, the said cope havinga plurality of perforations for a pouring gate and risers extendingtherethrough and communicating with the said casting and runner cavitiesand refractory liners for the said perforations extending through thecope and well thereabove.

10. The combination set forth in claim 9 in which the said liners haveclose fitting engagement with the cope in the said perforations.

11. A mold for casting metallic articles of considerable bulk andsurface areas, comprising a drag composed of green sand and providedwith an open topped casting'cavity for a major portion of the article tobe cast, sand cores in the said cavity in the drag, a plate like copecomposed principally of metal constituting a closure for the castingcavity against which the molten metal is cast and provided withperforations for a metal pouring gate and for risers, and heatinsulating liners for the said perforations extending through the copeand well thereabove, the cross sectional dimensions of metal solidifyingin the gate and risers being smaller than the said perforations in thecope.

12. A mold for casting metallic articles of considerable bulk andsurface area,'com prising a drag composed of green sand and providedwith an open topped casting cav- 1ty for a major portion of the articlesto be cast, and also provided with an open topped runner at one side ofand communicating with the said casting cavity, sand cores in the saidcavity in the drag, a plate like cope composed principally of metalconstituting a closure for the casting cavity against which the moltenmetal is cast and pro- .vided with a perforation opening into the saidrunner and a plurality of perforations opening into the casting cavity,a heat insulating cover for the said runner, and heat insula-tlng linersfor the said perforations extending through the cope and Wellthereabove.

13. A cope for a mold comprising a thin metal plate provided with aplurality of perforations extending therethrough and heat insulatingliners having close fitting engagement in the perforations and extendingthrough the cope and well thereabove, the passages formed by the linersbeing of smaller cross sectional dimensions than the perforations in thecope.

14. A cope for a mold comprising a thin metal plate provided with gateand riser perforations therethrough, liners for the said perforationscomposed of frangible.

material and forming passages through the perforations smaller in thecope, surface of the cope.

than the perforations and a core secured to the under- 15. A cope for amold comprising a thin 5 metal plate provided with perforationstherethrough,

periorations compose ate and riser iners for the d of frangiblematesignature.

CHARLES E. MAGILL.

